Intraband relaxation time effects on non-Markovian gain with many-body effects and comparison with experiment

Momentum-dependent and independent intraband relaxation time effects on a n on-Markovian (Gaussian line shape) many-body optical gain spectrum are pres ented. Our theoretical results are compared with experimental data as well as those obtained from a many-body gain model with a conventional Lorentzia n line shape function. We show that a Gaussian line shape gain model with a constant intraband relaxation time gives good agreement with experimental gain spectra and the inclusion of k-dependent intraband relaxation time yie lds slightly improved agreement. In the case of a Lorentzian line shape fun ction, it is found that the inclusion of the k-dependent carrier-carrier sc attering in the intraband relaxation time is important to obtain good agree ment with the experiment. This is because the Gaussian line shape function is steeper than the Lorentzian for a constant intraband relaxation time. Th e Gaussian line shape function with a constant intraband relaxation time re quires less computational time than that with a k-dependent intraband relax ation time; therefore, it is an efficient model for comparison with experim ental data.